Liquid-cooled internal combustion engine



April 19, 1966 H. MULLER 3,246,638

LIQUID-'COOLED INTERNAL COMBUSTION ENGINE Filed March 18, 1964 INVENTOR. m

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United States Patent 3,246,638 LlQUllD-CQOLED INTERNAL tCMBUTEON ENGINE Hans Mtiiler, 19 fin Rosental, Andernach (Rhine), Germany Filed Mar. 18, 1964, Ser. No. 353,213 Claims priority, application Germany, Mar. 20, 1963, H 48,566 15 Claims. ((11. 123-4172) The present invention relates to internal combustion engines, and more particularly to two-stroke cycle internal combustion engines. Still more particularly, the invention relates to an improved cylinder block for liquidcooled two-stroke cycle engines.

It is known to cast the cylinders and the crankcase of an internal combustion engine enbloc and to provide a separate casting, called cylinder head, which is bolted to the top of the cylinder block to close the upper ends of the cylinders. Thus, the cylinder head actually encloses a portion of each combustion chamber. A serious drawback of such engines is that the abutting faces of the two castings must be machined with considerable precision in order to avoid uncontrolled leakage, and the provision and maintenance of satisfactory seals also presents a grave problem.

Accordingly, it is an important object of my invention to provide a cylinder block for liquid-cooled two-stroke cycle interval combustion engines wherein the walls surrounding the combustion chambers form a one-piece casting with attendant elimination of sealing problems.

Another object of the invention is to provide a cylinder block of the just outlined characteristics wherein the cooling jackets of the individual cylinders may be readily assembled or taken apart to afford access to the liquidcontaining compartments of the cylinder block, and wherein such jackets may be sealed in a very simple manner with minimum of sealing material and without necessitating excessive precision finishing of their components.

A further object of the invention is to provide a cylinder block for a V-type two-stroke cycle internal combustion engine wherein the jackets may be assembled or taken apart with little loss in time and without necessitating removal of spark plugs or other component parts of the engine.

With the above objects in view, one feature of my invention resides in the provision of a water-cooled twostr-oke cycle internal combustion engine which comprises a plurality of cylinders forming one or more banks of cylinders and wherein each cylinder comprises a main body portion defining a combustion chamber and having an integral top portion at one end of the combustion chamber, a jacket including a cylindrical portion disposed around and forming a one-piece unit with the main body portion, a cover overlapping the top portion and adjacent to the cylindrical portion of the jacket, and fasteners securing the cover to the cylindrical portion of the jacket.

The top portion of each cylinder is provided with a centrally located tapped hole which may receive a spark plug or another igniter device, and each cylinder further comprises a sealing ring which is received between a pair of annuli respectively provided on the cover and on the top portion and serving to maintain the sealing ring in deformed condition so as to prevent escape of coolant from a compartment which is defined by the main body portion and the jacket of each cylinder. Each cover is further provided with a concentric opening which registers with the respective hole. It will be noted that the entire cylinder block may comprise a main casting and a series of covers which are detachably secured to the cylindrical portions of the respective jackets.

3,24%,638 Patented Apr. 19, 1966 The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved cylinder block itself, however, both as to its construction and the mode of assembling the same, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of a specific embodiment with reference to the accompanying drawing the single illustration of which is an end elevational view of a liquid-cooled V-type two-stroke cycle internal combustion engine, one of the cylinders being shown in partial vertical section.

Referring to the drawing, there is shown a cylinder block CB including two banks of cylinders, 1, 1'. The first cylinder 1 of each bank conceals the other cylinders 1' one of which is shown in part behind the brokenaway portion of the left-hand cylinder 1. Each cylinder includes a cylindrical main body portion 1a having an integral top portion 1b which is provided with a centrally located tapped hole 1c arranged to receive a spark plug or another suitable igniter device. Each cylinder further comprises a liquid-containing jacket 2 including a cylindrical portion 2a which is integral with the main body portion 1a and a detachable cover 3 secured to the cylindrical portion 2a by a series of bolts 6, 7 or by similar fasteners. The conical wall 3a of the cover 3 is spaced from the top portion 1b so that these parts define an annular end section 10a of a cooling compartment 10 which is defined by the main body portion 1a and by the cylindrical portion 2a of the jacket 2. The diameter of the annular end section 10a decreases in a direction toward the hole 10. The port-ions 2a, 3a of the jacket 2 are formed with closely adjacent flanges 5, 4 which compress a ring-shaped sealing element 11 when the bolts 6, 7 are driven home. The top wall 8 of the cover 3 is provided with an inwardly extending annular portion 8a which surrounds with play an annular extension 1d of the top portion 1b. The annular space between the parts 1d, 8a accommodates an elastically deformable O-ring 9 which forms a liquid-tight seal between the jacket 2 and main body portion 1a. It will be noted that the maximum diameter of the deformed ring 9 is less than the axial length of the annular space in which the ring is received so that the surfaces surrounding this space need not be finished with a high degree of precision. It normally sufiices if the diameters of the cylindrical surfaces which surround the ring 9 remain within certain limits to in- Sure that the ring is deformed in sealing engagement with the annuli 1d and 8a. Also, the end faces of the flanges 4, 5 need not be finished with great accuracy because the sealing ring 11 suffices to insure satisfactory sealing action when the bolts 6, 7 are screwed tight.

The top wall 8 of the cover 3 is provided with a cen tral opening 8b which registers with the hole 1c to allow for insertion or removal of the igniter device. The hole 10 communicates with the combustion chamber 12 which is defined by the portions 111, 1b of the cylinder.

The drawing further illustrates the condu-itry which serves to supply and to withdraw water or another liquid coolant from the compartments 1%) in the jackets 2.

The cylinder block CD is a casting wherein the main body portion 1a of each cylinder forms an integral unit with the respective jacket portion 2a.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adapta tions should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A cylinder block for water-cooled two-stroke cycle internal combustion engines, comprising a plurality of cylinders each including a main body portion defining by itself a combustion chamber and having an integral top portion at one end of said chamber, said top portion having a concentrically located tapped hole arranged to receive an igniter device and an annular extension surrounding said hole, a jacket including a cylindrical portion disposed around and forming a one-piece casting with said main body portion, and a cover overlapping said top portion and adjacent to said cylindrical portion, said cover having a concentric opening registering with said hole and an annular portion surrounding and spaced from said annular extension, a ring of deformable material received between said extension and said annular portion to provide an annular seal between said top portion and said cover, and fastener means securing said cover to said cylindrical portion and biasing said cover toward said top portion, whereby said ring is axially compressed and forced to expand radially, thus substantially filling the space between said extension and said annular portion, and providing a seal.

2. A cylinder block as set forth in claim 1, wherein said main body portions and said cylindrical portions of all cylinders together form a one-piece casting.

3. A cylinder block as set forth in claim 1, wherein each cylindrical portion comprises an annular flange at a point adjacent to the respective top portion and wherein each of said covers comprises an annular flange adjacent to the flange of the respective cylindrical portion, said fastener means comprising bolts securing said flanges to each other.

4. A cylinder block as set forth in claim 1, wherein said jackets and the respective main body portions define between themselves cooling compartments each of which extends to the annular portion of the respective cover.

5. A cylinder block as set forth in claim 1, wherein said rings are O-rings and wherein the axial length of said extensions exceeds the maximum diameters of the respective O-r-ings in deformed condition thereof.

6. A cylinder block as set forth in claim 1, wherein said jackets and the respective main body portions define between themselves annular compartments, each of said compartments having an annular end section whose diameter diminishes in a direction toward the respective opening.

7. In a cylinder block, a cylinder having an open end and including an annular extension surrounding said open end, said annular extension having an exposed end face and a peripheral recess extending inwardly from said end face; a deformable annulus received in said peripheral recess; a cover having an axially extending annular portion surrounding said recess and a radially inwardly extending annular portion overlying said recess when said cover is positioned on said open end of said cylinder; and fastener means securing said cover to said cylinder and biasing said radially extending annular portion of said cover against said annulus so that the latter expands radially and provides a seal between said cylinder and said cover.

8. In a cylinder block, a one-piece cylinder having an end formed with an axially extending opening and including an annular extension surrounding said opening, said annular extension having an exposed end face and a pcripheral recess extending inwardly from said end face; a deformable annulus received in said peripheral recess; a cover adapted to overlie said end and formed with a bore adapted to register with said opening, said cover having an axially extending annular portion surrounding said recess and a radially inwardly extending annular portion overlying said recess when said cover is positioned on said end of said cylinder; and fastener means securing said cover to said cylinder and biasing said radially extending annular portion of said cover against said annulus so that the latter expands radially and provides a seal between said cylinder and said cover.

9. In a cylinder block, a one-piece cylinder having an end formed with an axially extending opening and including an annular extension surrounding said opening, said annular extension having an exposed end face and a peripheral recess extending inwardly from said end face; a deformable annulus received in said peripheral recess; a cover adapted to overlie said end and formed with a bore adapted to register with said opening, said cover having an axially extending annular portion surrounding said recess and a radially inwardly extending annular portion overlying said recess when said cover is positioned on said end of said cylinder; and fastener means securing said cover to said cylinder and biasing said radially extending annular portion of said cover against said annulus in axial direction of said cylinder whereby said annulus is axially compressed and caused to radially expand so as to provide a seal between said cylinder and said cover.

10. In a cylinder block, a cylinder having an end formed with a centrally located tapped hole arranged to receive an igniting device inserted in axial direction of said hole; said cylinder including an annular extension surrounding said hole and said annular extension having an exposed end face and a peripheral recess extending inwardly from said end face; a cover overlying said end and being formed with an opening registering with said hole, said cover having an axially extending annular portion surrounding said recess and a radially inwardly extending portion overlying said recess; a ring of deformable material received in said recess intermediate said extension and said annular portion; and fastener means securing said cover to said cylinder and biasing said radially extending portion of said cover against said ring of deformable material whereby the latter expands radially and provides a seal between said cylinder and said cover.

11. In a cylinder block, a cylinder having an end formed with a centrally located tapped hole arranged to receive an igniting device inserted in axial direction of said hole, said cylinder cylinder including an annular extension surrounding said hole and said annular extension having an exposed end face and a peripheral recess extending inwardly of said end face; a cover overlying said end and being formed with an opening registering with said hole, said cover having an axially extending annular portion surrounding said recess and a radially inwardly extending portion overlying said recess; a ring of deformable material received in said recess intermediate said extension and said annular portion; and fastener means securing said cover to said cylinder and biasing said radially extending portion of said cover against said ring of deformable material in axial direction of an igniting device received in said hole whereby said ring is axially compressed and expands radially, thereby providing a seal between said cylinder and said cover.

12. In a cylinder block, a cylinder having an end formed with a centrally located tapped hole arranged to receive an igniting device inserted in axial direction of said hole, said cylinder including an annular extension surrounding said hole and said annular extension having an exposed end face and a peripheral recess extending inwardly from said end face; a cover overlying said end and being formed with an opening registering with said hole, said cover having an axially extending annular portion surrounding said recess and a radially inwardly extending portion overlying said recess; a ring of deformable material received in said recess intermediate said extension and said annular portion; and bolt means extending parallel to said axial direction of said hole, said bolt means securing said cover to said cylinder and biasing said radially extending portion of said cover against said ring of deformable material whereby the latter expands radially and provides a seal between said cylinder and said cover.

13. An arrangement as set forth in claim 12 wherein said cylinder and said cover are each formed with a plurality of bores located radially outwardly of said annular extension and said annular portion, respectively, at least the bores in said cylinder being tapped and re spective ones of said bores in said cylinder and cover registering with one another, said bolt means being screwthreaded and being threadingly received in the tapped ones of said bores, whereby said cover is secured to said cylinder.

14. An arrangement as set forth in claim 12, wherein said cylinder and said cover are each formed with a plurality of bores located radially outwardly of said annular extension and said annular portion, respectively, all of said bores extending axially parallel with said hole in said cover, biased toward said cylinder in axial direction of said hole in said cover, thereby axially compressing said ring of deformable material and causing it to expand radially, at least the bores in said cylinder being tapped and respective ones of said bores in said cylinder and cover registering with one another, said bolt means being screw-threaded and being threadingly received in the tapped ones of said bores, whereby said cover is secured to said cylinder.

15. In a cylinder block for water-cooled two-stroke cycle internal combustion engines including a unitary cylinder open at one end and a coolingwater jacket provided with a covervformed with an opening for insertion thereinto of an ignition device having a longitudinal axis, the improvement consisting of forming an end face of said cylinder at said open end thereof, and an underface of said cooling-water jacket facing said end face of said cylinder, respectively with complementary annular recesses, disposing in the annular space defined by said recesses a ring of deformable sealing material, and securing said cooling-Water jacket to said cylinder with bolts extending parallel to said axis of said ignition device, whereby as said underface of said cooling-water jacket is biased towards said end face of said cylinder, said ring therebetween is axially compressed and expands radially, thus establishing a seal between said underface and said end face.

References Cited by the Examiner UNITED STATES PATENTS 968,545 8/1910 Dodge. 1,179,053 4/1916 Twombly. 2,150,535 3/1939 Wintzer.

FOREIGN PATENTS 122,554 1/1919 Great Britain.

KARL J. ALBRECHT, Primary Examiner. 

1. A CYLINDER BLOCK FOR WATER-COOLED TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINES, COMPRISING A PLURALITY OF CYLINDERS EACH INCLUDING A MAIN BODY PORTION DEFINING BY ITSELF A COMBUSTION CHAMBER AND HAVING AN INTEGRAL TOP PORTION AT ONE END OF SAID CHAMBER, SAID TOP PORTION HAVING A CONCENTRICALLY LOCATED TAPPED HOLE ARRANGED TO RECEIVE AN IGNITER DEVICE AND AN ANNULAR EXTENSION SURROUNDING SAID HOLE, A JACKET INCLUDING A CYLINDRICAL PORTION DISPOSED AROUND AND FORMING A ONE-PIECE CASTING WITH SAID MAIN BODY PORTION, AND A COVER OVERLAPPING SAID TOP PORTION AND ADJACENT TO SAID CYLINDRICAL PORTION, SAID COVER HAVING A CONCENTRIC OPENING REGISTERING WITH SAID HOLE AND AN ANNULAR PORTION SURROUNDING AND SPACED FROM SAID ANNULAR EXTENSION, A RING OF DEFORMABLE MATERIAL RECEIVED BETWEEN SAID EXTENSION AND SAID ANNULAR PORTION TO PROVIDE AN ANNULAR SEAL BETWEEN SAID TOP PORTION AND SAID COVER, AND FASTENER MEANS SECURING SAID COVER TO SAID CYLINDRICAL PORTION AND BIASING SAID COVER TOWARD SAID TOP PORTION, WHEREBY SAID RING IS AXIALLY COMPRESSED AND FORCED TO EXPAND RADIALLY, THUS SUBSTANTIALLY FILLING THE SPACE BETWEEN SAID EXTENSION AND SAID ANNULAR PORTION, AND PROVIDING A SEAL. 